1 files changed, 57 insertions, 0 deletions
diff --git a/test/pos/cours2c.scala b/test/pos/cours2c.scala
new file mode 100644
index 0000000000..c2e4b221d5
--- /dev/null
+++ b/test/pos/cours2c.scala
@@ -0,0 +1,57 @@
+module m1  {
+
+  def average(x: Double, y: Double) = (x + y)/2;
+  def abs(x: Double): Double = if (x < 0) - x else x;
+  def isCloseEnough(x: Double, y: Double) = abs((x - y) / x) < 0.001;
+
+  def search(f: Double => Double, negPoint: Double, posPoint: Double): Double = {
+    val midPoint = average(negPoint, posPoint);
+    if (isCloseEnough(negPoint, posPoint))
+      midPoint
+    else {
+      val testVal = f(midPoint);
+      if (testVal > 0) search (f, negPoint, midPoint)
+      else if (testVal < 0) search (f, midPoint, posPoint)
+      else midPoint
+    }
+  }
+
+  def halfIntervalMethod(f: Double => Double, a: Double, b: Double): Double = {
+    val aval = f(a);
+    val bval = f(b);
+    if (aval < 0 && bval > 0) search(f, a, b)
+    else if (bval < 0 && aval > 0) search(f, b, a)
+    else error("Values are not of opposite sign")
+  }
+}
+
+module m2 {
+
+  def abs(x: Double): Double = if (x < 0) - x else x;
+  def isCloseEnough(x: Double, y: Double) = abs((x - y) / x) < 0.001;
+  def average(x: Double, y: Double) = (x + y)/2;
+
+  def fixedPoint(f: Double => Double, firstGuess: Double) = {
+    def try(guess: Double): Double = {
+      val next = f(guess);
+      if (isCloseEnough(guess, next)) next
+      else try(next)
+    }
+    try(firstGuess);
+  }
+
+  def sin(x: Double): Double = x;
+  def cos(x: Double): Double = x;
+
+  val result = fixedPoint((y => sin(y) + cos(y)), 1.0);
+
+  def averageDamp(f: Double => Double)(x: Double) =
+    average(x, f(x));
+
+  def sqrt(x: Double) =
+    fixedPoint(averageDamp(y => x/y), 1.0);
+
+  def cubeRoot(x: Double) =
+    fixedPoint(averageDamp(y => x/(y*y)), 1.0);
+}
+